keyboard not responsive after sleep

I also have this problem. I've reset my SMC and PRAM. No effect.

The other response, to If your Apple wireless mouse, keyboard, or trackpad aren't working as expected - Apple Support below, is also not relevant.

My situation:
2012 Non-Retina MacBook Pro

KUL ES-87 external USB keyboard

Everything was fine on El Capitan. (I was never able to use my keyboard to wake the computer, but it always worked fine after I woke my computer with the mouse.)

On Sierra, if I sleep my computer briefly, keyboard works fine on wake.

If I leave my computer asleep for a long period (hard to know the threshold), then my keyboard is unresponsive on wake.

Unplugging and re-plugging my keyboard makes it work again.

This is bearable but extremely annoying, and it clearly has something to do with Sierra. :\

Please reset the SMC several times and ensure all peripherals are disconnected when doing so.

iMac SMC and PRAM reset

Also try each step at > If your Apple wireless mouse, keyboard, or trackpad aren't working as expected - Apple Support